My understanding is the calisthenics/gymnastics style weight training was much more common near the beginning of the century. My question, what did the cultural fitness transition to bench/squat/deadlift look like? Did it have to do with the rise of Bodybuilding as a mainstream discipline? Arnold in the movies? Infomercials? Rocky style training montages? Or am I wrong, and weights were always the 'every man's' understanding of what getting strong would look like?
I suppose the core of my question, has to the do with the evolution of cultural perceptions of what fitness 'looked' like, and what kind of apparatus/exercises you might see if you went to a place where people were training in 1914, vs 2014. I realize this is a very broad topic, but if you can even point me towards some resources that could possibly help me refine my question, I'd appreciate it.
I can only give a partial answer and I cannot even source it, as I have pieced this together from many sources read on and offline, but if no better one comes this can be useful (if a better one comes, delete it):
barbell type weight lifting was already there at the first 1896 Olympics, however the big question is when did it become mainstream amongst those people who don't identify as weight lifters, as I think this is what you ask
Body building as such increased a growing popularity all through the 20the century, but the key moment of change would be the Pumping Iron movie n 1977. This was the moment of catapulting it into the mainstream. If you really want a starting moment where Average Fit Guy would be seen as the big bench presser and not the guy who can do 100 push ups, I think the absolutely best resource is watching Pumping Iron.
However the kind of body building books I purchased in the 1980's to 1990's and the magazines did NOT promote traditional Olympics style weight lifting much. They generally recommended one compound and one isolated movement for each muscle, they targeted muscles, not lifts. For example leg would be leg press or squats, leg extensions, leg biceps, calves. A true body builder would do at least 2 types of calves exercises (standing, sitting) it was one of the hardest muscles to get to grow. I don't even remember hearing about deadlifts,
This is markedly different from the current trend of Stronglift 5 x 5 and Starting Strength, which do for example squats and deadlifts, but they are seen as lifts, not leg exercises per se. This current trend harkens back to old fashioned Olympic lifting and also to powerlifting, and is generally not quite considered the same thing as body building as such. Often it is called weight lifting or strength training to separate it from body building which uses more isolation exercises. This current trend is partially based on research into how these big isolation exercises are good for testosterone.
So, we see TWO changes here. The first one, from "100 push ups guy to body builder" as the definition of fitness went constantly through the 20th century, Pumping Iron was a turning point, the Conan movie too etc. You can check the change of the male ideal by simply googling Superman or Spiderman comics from say 1960 and 1990, the difference is about thirty kilo of muscle. You can google "Johnny Weismüller Tarzan" and wonder how such a thin guy (a swimmer) was considered for a Tarzan movie back then. These show how the male ideal used to be thinner. It changed slowly, Reg Parks Hercules movies in the 1960's were probably important, Arnold's Conan in 1982 even more, but I would say the turning point was Pumping Iron.
The second change was - and actually it seems really recent for me (Mark Rippetoe etc.) is changing from the compound + isolation view of body building, from its looks orientedness, into isolation-only, basically popularizing power / weight lifting, strength training over body builder looks. As one Redditor put it "I am not a body builder: my hobby is picking up heavy things." It is a marked, second change.
Again I don't really have much in the way of sources but Pumping Iron, 1977 is a must-watch on YouTube. You can look at the modern, strength training approach (which reinvents the old Olympic approach) at any Mark Rippetoe type book, while body building books from the 1980's show the older more isolation oriented approach.
Again sorry mods I know it is not quite up to the standards but I hope it helps. If a better one comes around delete it.
EDIT: have seen you want to go back earlier than the 1960's. Well, in the earler half of the 20th century the definitive Fit Guy would be Charles Atlas. You can find a PDF copy of his training manual here: http://www.angelfire.com/ny5/shenandoah/CA/Charles_Atlas.pdf as you can see it is mostly calisthenics.